94 Mr. E. A. Smith on new 



Radida with teeth in seven series (3, 1.3), central smallest ; 

 recurved edge notched at each side, with a conspicuous cutting- 

 edge; inner or first lateral obliquely subquadrate, much pro- 

 duced at the outer base into a rostrate extremity, with three 

 denticles on the recurved cutting-edge ; second lateral larger 

 than the rest, oblique, incurved, margin tricuspidate ; outer 

 or third lateral narrow, more slender at the base than above, 

 curved over towards the adjacent tooth, and with five or six 

 unequal denticles on the edge. 



Operculum rich brown, horny, narrow, striated externally 

 with lines of growth from the paucispiral nucleus, which is 

 nearly terminal ; lower surface with a broad glossy band or 

 thickening along the outer or right margin, occupying about 

 half the surface ; placed transversely across the dorsal part of 

 the foot. Length (from a semiadult shell 20 millim. long) 

 7 millim., diameter 3^. 



Mr. Gwatkin, who has had much experience, kindly 

 examined the radula of this genus, and informs me that he 

 is inclined to believe that Nassopsis will find its nearest allies 

 in the Cerithiidge, and not amongst the Littorinoids as I had 

 suggested. It also seems to me to bear considerable resem- 

 blance to Planaxis. 



In general construction the operculum is very like that of 

 many species of Melam'a, but the peculiar solidity of the shell 

 and the slight notch at the base of the columella, besides 

 certain differences in the radula, may be sufficient to separate 

 this and allied species as a distinct group. 



Syrnolopsis {Anceya) Giraudi, var. 



A single specimen, kindly submitted to me for examination 

 by Mr. S. I. Da Costa, agrees in most respects with ^I. Bour- 

 guignat's description. It differs, however, in colour, being 

 of a red tint with a white zone around the middle of the 

 whorls. It does not exhibit the palatal lirje in the aperture, 

 but these may be too iar within to be visible. In adult speci- 

 mens of Syrnolojjsi's lacusfris the lirai cannot be seen until the 

 lip is broken away to some extent. As far as I can discover 

 the only distinction separating Anceya from Syrnolopsis is 

 one of sculpture. The type of Syrnolopsis has smooth whorls, 

 whereas that of Ayiceya is lonyitudinaUy costate. If scul(>- 

 lurc be admitted as a generic character there is no reason wjjy 

 Syrnolo2>sis carinifera should not be regarded as the type of a 

 third genus characterized hy sj>iral ridges. The general form 

 of the aperture is the same in all three forms ; it is slightly 

 oblique and has an upper and basal broad sinus or slight 



